Flat key ring



FIG. 1 is a top plan view of an embodiment of a flat key ring;

FIG. 2 is a front top perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a right-side elevation view thereof; and,

FIG. 6 is a left-side elevation view thereof.

The broken lines shown in the drawings depict portions of the flat key ring that form no part of the claimed design. 

CLAIM The ornamental design for a flat key ring, as shown and described. 